how to change hyperlink color in css

1a {
2  background-color: red;
3  color: white;
4  padding: 1em 1.5em;
5  text-decoration: none;
6  text-transform: uppercase;
7}

1a {
2  background-color: red;
3  color: white;
4  padding: 1em 1.5em;
5  text-decoration: none;
6  text-transform: uppercase;